Cleaning web

ABSTRACT

An elongated, flexible cleaning web is attached at one end to spaced, endless timing belts by means of a tow strap having the form of a catenary curve to pull the cleaning web along an endless path to clean a flexible photoconductor. The catenary curve of the two strap reduces longitudinal wrinkling of the web, particularly as it passes around corners. Lateral wrinkling is reduced by not attaching the other end of the web.

United States Patent Alphonse B. Di Francesco Rochester, N.Y.;

James D. Shaw, Piney Point, Md. 806,889

Mar. 13, 1969 Inventors Appl. No Filed Patented Aug. 10, 1971 Assignee Eastman Kodak Company Rochester, N.Y.

CLEANING WEB 10 Claims, 2 Drawing Figs.

198/152,1l;355/15;193/1;l5/l 5,99,256.5

[56] References Cited UNITED STATES PATENTS 3,380,355 4/1968 Eichorn .1 355/15 3,510,903 5/1970 Stoever et a1 355/15 X Primary Examiner-John M. Horan Assistant Examiner-Russell E. Adams, Jr. Arlarneys- Robert W. Hampton and Gary D. Fields ABSTRACT: An elongated, flexible cleaning web is attached at one end to spaced, endless timing belts by means ofa tow strap having the form of a catenary curve to pull the cleaning web along an endless path to clean a flexible photoconductor The eatenary curve ofthe two strap reduces longitudinal wrin kling of the web, particularly as it passes around corners. Lateral wrinkling is reduced by not attaching the other end of the web.

PATENTED AUG 10 I97:

COLLECTOR CONTAINER VACUUM ALPHONSE B. DI FRANCESCC JAMES D. SHAW INVENTORS ATTORNEYS CLEANING WEB and more particularly to a web for cleaning toner particles from a photoconductive surface, which web is attached to drive means by an end in the form of a catenary curve.

2. Description of the Prior Art In a conventional electrophotographic apparatus an electrostatic image is formed on a photoconductive surface. This image is then toned by a suitable developing material, such as a drytoner powder. The developed toner image is then transferred to a receiver. However, a small amount of residual toner will remain on the photoconductive surface which must be removed therefrom prior to the forming and transfer of subsequent images to prevent ghost images from being formed during subsequent transfers. Various attempts have been made to clean photoconductive surfaces. One way is by the use of an endless web which engages the photoconductive surface along a portion of its path of travel to clean it for reuse. However, it is difficult to install and remove an endless web because suitable means must be provided in the web drive system to relieve tension on the web while a worn one is being replaced with a new one. The web tends to wrinkle when tension is applied thereto. If the web is not held under tension but is merely connected to the drive means, such as timing belts, it still has a tendency to wrinkle, particularly as it passes around curved surfaces, such as rollers, etc. If the web stretches, the tension must be adjusted during use to prevent further wrinkling.

SUMMARY OF THE INVENTION In accordance with this invention, means having the form of a catenary curve, such as a strap, is attached to one end of an elongated cleaning web. The strap is provided with suitable means for attaching it to drive means which moves it past a photoconductive surface in frictional engagement therewith to remove residual toner particles therefrom. Conveniently, the elongated web may be sufficiently long to overlap the attaching means. More particularly, the drive means may take the form of a pair of spaced timing belts extending around two or more spaced rollers. The catenary strap is attached across one end of the web with ends thereof fastened to the timing belts, respectively, as by snap fasteners. The web extends all the way around the path with the opposite end thereof overlapping the snap fasteners so that they cannot engage or damage the photoconductor. The catenary curve shape reduces wrinkling or buckling of the web in a longitudinal direction as it passes around the rollers. By having the opposite end loose, lateral wrinkling will be reduced since the cleaning web will tend to be pulled tight as it moves along its path.

Additional features of this invention will become apparent from the description which follows, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic side elevation of the cleaning device of this invention, partly in section to show details thereof; and

FIG. 2 is a perspective view of the cleaning web, with parts broken away for clarity of illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with this invention, a photoconductor 10, which may be in the form of an endless belt, may be driven past a conventional charging station, an exposure station, developing station, and a transfer station, such as illustrated in commonly assigned US. Pat. application Ser. No. 725,742, filed May l, I968, now US. Pat. No. 3,5l0,'903 and finally past a web cleaning device D, which is adapted to remove residual toner particles from photoconductor 10 so that it may be reused again and again. The photoconductor may include a photoconductive material on a conductive backing, as is common in the art.

As best seen in FIG. 2, the cleaning device includes an elongated cleaning web 11 which is attached to a pair of spaced timing belts 12 extending around and engages serrated ends of rollers 13, 14, and 15, as shown. Conveniently, one of the rollers may be a driven roller for moving the timing belts through an endless path. A tow strap 16, having the form of a catenary curve is attached to the leading end of elongated web 11, the ends of tow strap 16 being attached to timing belts 12, as by snap fasteners 17. Cleaning web 11 is so dimensioned that the trailing end 18 thereof will overlap snap fastener 17 and tow strap 16, as shown in FIG. 1, when being pulled through the endless path to prevent the snap fasteners and tow strap from scratching or otherwise damaging photoconductor 10 as they come in contact therewith. Advantageously, the cleaning web is driven in a direction opposite to that in which the photoconductor is moving. The catenary curve shape of the tow strap reduces wrinkling longitudinally along the cleaning web, particularly as it passes around rollers l3, l4, and 15. Since end 18 is unattached, the web tends to be pulled tight in a longitudinal direction tending to reduce lateral wrinkling.

To facilitate cleaning of photoconductor 10, an AC Corona 19 may be provided adjacent cleaning web 11, in the vicinity of photoconductor 10, as shown, to neutralize any charge on the residual toner particles so that they may be more easily picked up by the cleaning web. Toner particles may then be cleaned from the cleaning web by beaters or brushes 20. The toner particles thus separated may be exhausted by air pulled through inlet 21 which passes through cleaning web I] and carries the loosened toner particles with it through outlet 22 into a vacuum collector container 23.

From the foregoing, the advantages of this invention are readily apparent. An elongated cleaning web is provided which may be attached to endless timing belts by means of a tow strap having the shape of a catenary curve, thereby reducing longitudinal wrinkling of the cleaning web as it passes around support rollers. Furthermore, the cleaning web may be dimensioned so as the trailing end thereof overlaps the fastening means which attach the tow strap to the timing belts to prevent scratching or other damage to the photoconductor during cleaning. Also, by having the trailing end loose, lateral wrinkling is reduced.

The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

lclaim:

l. A cleaning device for cleaning residual toner particles from a photoconductive surface wherein drive means is provided for moving said cleaning device along an endless path past said photoconductive surface in frictional engagement therewith to remove said residual toner particles therefrom, said device comprising:

an elongated cleaning web having a leading end and a trailing end;

tow means at said leading end of said web for pulling said web along said endless path and having a catenary curve, configuration to reduce longitudinal wrinkling of said cleaning web as said web is moved past said photoconductive surface;

means on said tow means for attaching said web to the drive means 2. A cleaning device, as claimed in claim 1, wherein:

said trailing end of said cleaning web is not attachable to the drive means so that said cleaning web is pulled tight in a longitudinal direction without lateral wrinkling as it is moved along said endless path past said photoconductive surface.

3. A cleaning device for cleaning residual toner particles from a photoconductive surface wherein drive means is provided for moving said cleaning device along an endless path past said photoconductive surface in frictional engagement therewith to clean said residual toner particles therefrom, said device comprising:

an elongated cleaning web having a leading end and a trailing end; and

a strap, having the shape of a catenary curve, attached to said leading end of said cleaning web, for coupling said cleaning web to said drive means to move said web along said endless path past said photoconductive surface without longitudinal wrinkling.

4. A cleaning device, as claimed in claim 3, further including:

fastening means on said strap for attaching said strap to the drive means.

5. A cleaning device for cleaning residual toner particles from a photoconductive surface, said device comprising:

an elongated cleaning web having a leading end and a trailing end;

web-moving means for moving said elongated web in an endless path past said photoconductive surface to clean residual toner particles therefrom; and

a tow strap, having the shape of a catenary curve, attached to said leading end of said elongated web and connected to said moving means for towing said web past said photoconductive surface without wrinkling.

6. A cleaning device, as claimed in claim 5, wherein:

said web-moving means includes a pair of spaced endless belts to which said tow strap is connected.

7. A cleaning device, as claimed in claim 6, wherein said web is dimensioned so that said trailing end thereof overlaps said tow strap to prevent damage to said photoconductive surface.

8. A cleaning device, as claimed in claim 6, further including:

snap means on said strap for attaching said strap to each of said endless belts, said trailing end of said web overlapping said tow strap.

9. A cleaning device, as claimed in claim 7, wherein:

said trailing end is not attached to said endless belts so that said cleaning web is pulled tight in a longitudinal direction so that it is moved through said endless path without lateral wrinkling.

10. In an electrophotographic apparatus including a flexible endless photoconductive member movable through an endless path in series past a charging station for placing an electrostatic charge on said photoconductive member, an exposure station for exposing said charged photoconductive member to a pattern of radiation to form an electrostatic image on said photoconductive member, past a developing station to tone said electrostatic image on said photoconductive member, past a transfer station to transfer the toned image from said photoconductive member to a receiver, and past a cleaning station to remove residual toner particles from said photocon ductive member, said cleaning station including a cleaning web having a leading end and a trailing end and being attached to a pair of spaced endless belts for moving said cleaning web along an endless path past said photoconductive member in frictional engagement therewith and in the opposite direction to the movement of said photoconductive member, and means for cleaning said cleaning web so that it may be used over and over again, said improvement comprising:

tow means at said leading end of said cleaning web having the configuration of a catenary curve; and

means on said leading end for attaching said web to said spaced endless belts, said catenary curve configuration tending to prevent longitudinal wrinkling of said cleaning web as it is pulled through said endless pathl 

1. A cleaning device for cleaning residual toner particles from a photoconductive surface wherein drive means is provided for moving said cleaning device along an endless path past said photoconductive surface in frictional engagement therewith to remove said residual toner particles therefrom, said device comprising: an elongated cleaning web having a leading end and a trailing end; tow means at said leading end of said web for pulling said web along said endless path and having a catenary curve configuration to reduce longitudinal wrinkling of said cleaning web as said web is moved past said photoconductive surface; means on said tow means for attaching said web to the drive means.
 2. A cleaning device, as claimed in claim 1, wherein: said trailing end of said cleaning web is not attachable to the drive means so that said cleaning web is pulled tight in a longitudinal direction without lateral wrinkling as it is moved along said endless path past said photoconductive surface.
 3. A cleaning device for cleaning residual toner particles from a photoconductive surface wherein drive means is provided for moving said cleaning device along an endless path past said photoconductive surface in frictional engagement therewith to clean said residual toner particles therefrom, said device comprising: an elongated cleaning web having a leading end and a trailing end; and a strap, having the shape of a catenary curve, attached to said leading end of said cleaning web, for coupling said cleaning web to said drive means to move said web along said endless path past said photoconductive surface without longitudinal wrinkling.
 4. A cleaning device, as claimed in claim 3, further including: fastening means on said strap for attaching said strap to the drive means.
 5. A cleaning device for cleaning residual toner particles from a photoconductive surface, said device comprising: an elongated cleaning web having a leading end and a trailing end; web-moving means for moving said elongated web in an endless path past said photoconductive surface to clean residual toner particles therefrom; and a tow strap, having the shape of a catenary curve, attached to said leading end of said elongated web and connected to said moving means for towing said web past said photoconductive surface without wrinkling.
 6. A cleaning device, as claimed in claim 5, wherein: said web-moving means includes a pair of spaced endless belts to which said tow strap is connected.
 7. A cleaning device, as claimed in claim 6, wherein said web is dimensioned so that said trailing end thereof overlaps said tow strap to prevent damage to said photoconductive surface.
 8. A cleaning device, as claimed in claim 6, further including: snap means on said strap for attaching said strap to each of said endless belts, said trailing end of said web overlapping said tow strap.
 9. A cleaning device, as claimed in claim 7, wherein: said trailing end is not attached to said endless belts so that said cleaning web is pulled tight in a longitudinal direction so that it is moved through said endless path without lateral wrinkling.
 10. In an electrophotographic apparatus including a flexible endless photoconductive member movable through an endless path in series past a charging station for placing an electrostatic charge on said photoconductive member, an exposure station for exposing said charged photoconductive member to a pattern of radiation to form an electrostatic image on said photoconductive member, past a developing station to tone said electrostatic image on said photoconductive member, past a transfer station to transfer the toned image from said photoconductive member to a receiver, and past a cleaning station to remove residual toner particles from said photoconductive member, said cleaning station including a cleaning web having a leading end and a trailing end and being attached to a pair of spaced endless belts for moving said cleaning web along an endless path past said photoconductive member in frictional engagement therewith and in the opposite direction to the movement of said photoconductive member, and means for cleaning said cleaning web so that it may be used over and over again, said improvement comprising: tow means at said leading end of said cleaning web having the configuration of a catenary curVe; and means on said leading end for attaching said web to said spaced endless belts, said catenary curve configuration tending to prevent longitudinal wrinkling of said cleaning web as it is pulled through said endless path. 